1. Field of the Invention
The present invention relates to an inkjet printhead, and more particularly, to a piezoelectric inkjet printhead including two silicon substrates and a method of manufacturing the same.
2. Description of the Related Art
An inkjet printhead is an apparatus that ejects very small droplets of printing ink on a printing medium in a desired position to print an image in a predetermined color. Inkjet printheads may be largely classified into thermal-drive inkjet printheads and piezoelectric inkjet printheads. The thermal-drive inkjet printhead produces bubbles using a thermal source and ejects ink due to the expansive force of the bubbles. The piezoelectric inkjet printhead applies pressure generated by deforming a piezoelectric material to ink and ejects the ink due to the generated pressure.
In a conventional piezoelectric inkjet printhead, a manifold, a plurality of restrictors, a plurality of pressure chambers, and a plurality of nozzles form an ink flow path and are disposed in a flow path forming plate, and a plurality of piezoelectric actuators are disposed over the flow path forming plate. The manifold is a path via which ink is supplied from an ink storage to each of the pressure chambers, and each of the restrictors is a path via which ink is supplied from the manifold to the corresponding pressure chamber. The pressure chambers are filled with ink to be ejected. The volume of each of the pressure chambers is varied due to the drive of the corresponding piezoelectric actuator to cause a pressure variation required for ejecting or injecting ink.
The formation of the flow path forming plate includes forming the ink flow path by processing each of a plurality of thin substrates formed of a ceramic material, a metal material, or a synthetic resin and stacking the thin substrates. Also, each of the piezoelectric actuators is formed over the pressure chamber by stacking a piezoelectric layer and an electrode for applying a voltage to the piezoelectric layer. Thus, a portion of the flow path forming plate, which forms a top wall of the pressure chamber, functions as a vibrating plate.
Operation of the conventional piezoelectric inkjet printhead having the above-described construction will now be described. When the vibrating plate is deformed due to the drive of the piezoelectric actuator, the volume of the pressure chamber is reduced, so that ink is externally ejected from the pressure chamber via nozzles due to a pressure variation of the pressure chamber. Thereafter, when the vibrating plate is restored to its original shape due to the drive of the piezoelectric actuator, the volume of the pressure chamber is increased, so that ink is supplied from the manifold through the restrictor into the pressure chamber due to a pressure variation.
As described above, since the conventional inkjet printhead is manufactured by stacking a plurality of substrates, a manufacturing process is complicated and a process of stacking a plurality of substrates leads to the occurrence of alignment errors.